<main>
    <h2>第一章：函数、极限与连续</h2>
    <p>本章包含函数概念、极限理论和连续性分析等内容。</p>
    
    <div class="section-links">
        <h3>连续性专题</h3>
        <ul>
            <li><a href="continuity/introduction.html">连续性概念引入</a></li>
            <li><a href="continuity/discontinuity-types.html">间断点分类</a></li>
            <li><a href="continuity/sinx-over-x.html">sin(x)/x 可视化</a></li>
            <li><a href="continuity/oscillation-discontinuity.html">振荡间断点演示</a></li>
        </ul>
    </div>
</main>